1. Field of Invention
The present invention is related to a mount for a light emitting device, the mount having an integrated reflector cup.
2. Description of Related Art
Semiconductor light emitting devices such as light emitting diodes (LEDs) are among the most efficient light sources currently available. Material systems currently of interest in the manufacture of high brightness LEDs capable of operation across the visible spectrum include group III–V semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials; and binary, ternary, and quaternary alloys of gallium, aluminum, indium, and phosphorus, also referred to as III-phosphide materials. Often III-nitride devices are epitaxially grown on sapphire, silicon carbide, or III-nitride substrates and III-phosphide devices are epitaxially grown on gallium arsenide by metal organic chemical vapor deposition (MOCVD) molecular beam epitaxy (MBE) or other epitaxial techniques. Often, an n-type layer (or layers) is deposited on the substrate, then an active region is deposited on the n-type layers, then a p-type layer (or layers) is deposited on the active region. The order of the layers may be reversed such that the p-type layers are adjacent to the substrate.
LEDs are often mounted on a submount, then packaged. FIG. 1 illustrates a package described in more detail in U.S. Pat. No. 6,274,924, “Surface Mountable LED Package.” LED 104 is attached to a submount 103. Leads 106 of leadframe 105 are electrically connected to the LED-submount combination. The LED-submount combination is disposed in a reflector cup 102 formed (such as by stamping) on a heat sink 100. Reflector cup 102 is designed to reflect any light emitted from the sides or bottom of LED 104 back toward the vertical axis of lens 108 so the light can be usefully extracted from the package. Submount 103 is generally larger than LED 104, in order to accommodate electrical contacts that must be made on submount 103. As a result, reflector cup 102 is large compared to the size of LED 104, thus reflector cup 102 significantly increases the size of the light source created by the package illustrated in FIG. 1.